Plugs

[charles@pricefarrington.c]

Hello:

I have been hibernating for a while and now and coming back online. I am running Champion RJ12Cs in the A4 and thought I might try the autolites for comparison. Anyone have the model no. for the autolites? Thanks for the input.

[keelcooler]

86 Autolites

[roadnsky]

They're also known as Autolite 437's

[Mo]

They're also known as Autolite 437's

Hi guys,

Are these the ones that run a little hotter. I'd have to look and see what is in mine now, however, I did buy the ones that ran hotter.

Thanks.

[roadnsky]

Hi guys,

Are these the ones that run a little hotter.

Yep. Hot! Hot! Hot!
Or 'mas caliente' for Neil

[67c&ccorv]

OK, here is the skill testing question;

(Dave Neptune you can not take part because I know you know!)

What does it mean when we say a spark plug runs "hotter" or "colder" than another plug

[roadnsky]

The heat range of a spark plug is determined by the temperature of the spark plug tip which is controlled by the amount and material type composite construction of the ceramic insulator on the tip which affects its thermal conductivity. The more the thermal conductivity of the spark plug tip the cooler the plug and vice versa.

[Mo]

Has to do with the plug itself...not the engine running hotter or colder.

If hot it is self cleaning ...fires at a higher temp (too hot can burn a hole in piston).

If plugs are too cold you are always cleaning them from carbon build-up because they are not firing at a temp high enough to burn all the combustible material.

...that's the quick answer.

[charles@pricefarrington.c]

Ok, dropped the autolite 437s in today. The Champions did me no wrong but seemed a bit sootie after a year and about 150 hours. Took lots of trips with no wind. We'll test the autolites. The Captain is moving the boat to Anacortes, closer to the San Juan islands, for the year.

[Mo]

Ranger 29...good solid boat.

[sastanley]

charles, I know you've already changed them but the other Autolites if I recall are 303's. At least that is what I think I have in my spares box.

By the way - I've run the RJ8, RJ12C, 303, & 437's in my boat..I am not sure I can tell the difference. This year, just because it is what they had, it'll be the RJ12C's again.

[charles@pricefarrington.c]

I had to run around for the RJ's but they had the 437's on hand so I got them and installed and rounded up the rest of the RJ's and will use them probably next change or as spares. Hopefully I'll never need them.

The only other project to tackle is changing the impellers. The raw water location will be tough and I am training to for my contortionist skills to get to it....

[smosher]

I tried the 437 last year and they fouled after 3 hours use, went back to the champion rj12's

Steve

[charles@pricefarrington.c]

Did she start running rough is that how you knew they were fouled?

[smosher]

Yes Exactly, took them out and put in some spare rj12's and problem went away.

They were covered i muck,